Christmas lights (also known informally as fairy lights) are lights used for decoration in preparation for Christmas and for display throughout Christmastide. The custom goes back to the use of candles to decorate the Christmas tree in Christian homes in early modern Germany.[1][2] Christmas trees displayed publicly and illuminated with electric lights became popular in the early 20th century. By the mid-20th century, it became customary to display strings of electric lights as along streets and on buildings Christmas decorations detached from the Christmas tree itself. In the United States, it became popular to outline private homes with such Christmas lights in tract housing beginning in the 1960s. By the late 20th century, the custom had also been adopted in non-western countries / regions, notably in Japan and Hong Kong.

The Christmas tree was adopted in upper-class homes in 18th-century Germany, where it was occasionally decorated with candles, which at the time was a comparatively expensive light source. Candles for the tree were glued with melted wax to a tree branch or attached by pins. Around 1890, candleholders were first used for Christmas candles. Between 1902 and 1914, small lanterns and glass balls to hold the candles started to be used. Early electric Christmas lights were introduced with electrification, beginning in the 1880s.

The illuminated Christmas tree became established in the United Kingdom during Queen Victoria's reign, and through emigration spread to North America and Australia. In her journal for Christmas Eve 1832, the delighted 13-year-old princess wrote, "After dinner.. we then went into the drawing-room near the dining-room. There were two large round tables on which were placed two trees hung with lights and sugar ornaments. All the presents being placed round the trees".[7] Until the availability of inexpensive electrical power in the early twentieth century, miniature candles were commonly (and in some cultures still are) used.

In the United Kingdom, electrically powered Christmas lights are generally known as fairy lights. In 1881, the Savoy Theatre, London was the first building in the world to be lit entirely by electricity.[8]Sir Joseph Swan, pioneer of the incandescent light bulb, supplied about 1,200 Swan incandescent lamps, and a year later, the Savoy owner Richard D'Oyly Carte equipped the principal fairies with miniature lighting supplied by the Swan United Electric Lamp Company, for the opening night of the Gilbert and Sullivan opera Iolanthe on 25 November 1882.[9] The term 'fairy lights', describing 'a small coloured light used in illuminations' had already entered English:[10] its usage for a string of electrically powered Christmas lights has been common in the UK ever since.[11]

The first known electrically illuminated Christmas tree was the creation of Edward H. Johnson, an associate of inventor Thomas Edison. While he was vice president of the Edison Electric Light Company, a predecessor of today's Con Edisonelectric utility, he had Christmas tree light bulbs especially made for him. He proudly displayed his Christmas tree, which was hand-wired with 80 red, white and blue electric incandescent light bulbs the size of walnuts, on December 22, 1882 at his home on Fifth Avenue in New York City. Local newspapers ignored the story, seeing it as a publicity stunt. However, it was published by a Detroit newspaper reporter, and Johnson has become widely regarded as the Father of Electric Christmas Tree Lights. By 1900, businesses started stringing up Christmas lights behind their windows.[12] Christmas lights were too expensive for the average person; as such, electric Christmas lights did not become the majority replacement for candles until 1930.[13]

In 1895, U.S. President Grover Cleveland proudly sponsored the first electrically lit Christmas tree in the White House. It was a huge specimen, featuring more than a hundred multicolored lights. The first commercially produced Christmas tree lamps were manufactured in strings of multiples of eight sockets by the General Electric Co. of Harrison, New Jersey. Each socket took a miniature two-candela carbon-filament lamp.

From that point on, electrically illuminated Christmas trees, but only indoors, grew with mounting enthusiasm in the United States and elsewhere. San Diego in 1904, Appleton, Wisconsin in 1909, and New York City in 1912 were the first recorded instances of the use of Christmas lights outside.[13]McAdenville, North Carolina claims to have been the first in 1956.[14] The Library of Congress credits the town for inventing "the tradition of decorating evergreen trees with Christmas lights dates back to 1956 when the McAdenville Men's Club conceived of the idea of decorating a few trees around the McAdenville Community Center."[15] However, the Rockefeller Center Christmas Tree has had "lights" since 1931, but did not have real electric lights until 1956.[16] Furthermore, Philadelphia's Christmas Light Show and Disney's Christmas Tree also began in 1956.[17][18] Though General Electric sponsored community lighting competitions during the 1920s, it would take until the mid-1950s for the use of such lights to be adopted by average households.

Over a period of time,[clarification needed] strings of Christmas lights found their way into use in places other than Christmas trees. Soon, strings of lights adorned mantles and doorways inside homes, and ran along the rafters, roof lines, and porch railings of homes and businesses. In recent times, many city skyscrapers are decorated with long mostly-vertical strings of a common theme, and are activated simultaneously in Grand Illumination ceremonies.

In the mid-2000s, the video of the home of Carson Williams was widely distributed on the internet as a viral video. It garnered national attention in 2005 from The Today Show on NBC, Inside Edition and the CBS Evening News and was featured in a Miller television commercial.[19][20] Williams turned his hobby into a commercial venture, and was commissioned to scale up his vision to a scale of 250,000 lights at a Denver shopping center, as well as displays in parks and zoos.

Christmas lights (also called twinkle lights,holiday lights,mini lights or fairy lights), that are strands of electric lights used to decorate homes, public/commercial buildings and Christmas trees during the Christmas season are amongst the most recognized form of Christmas lighting. Christmas lights come in a dazzling array of configurations and colors. The small "midget" bulbs commonly known as fairy lights are also called Italian lights in some parts of the U.S., such as Chicago.

Christmas lights using incandescent bulbs are somewhat notorious for being difficult to troubleshoot and repair. In the 1950s and 1960s, the series circuit connected light sets would go completely dark when a single bulb failed. So in the fairly recent past, the mini-lights have come with shunts to allow a set to continue to operate with a burned out bulb. However, if there are multiple bulb failures or a shunt is bad, the string can still fail. There are two basic ways to troubleshoot this: a one by one replacement with a known good bulb, or by using a test light to find out where the voltage gets interrupted. One example made specifically for Christmas lights is the LightKeeper Pro. For additional information, see the troubleshooting section of the Holiday lighting technology article.

When Christmas light manufacturers first started using LEDs the colors seemed very dull and uninspiring. Even the white lights, which were typically single-chip LEDs, glowed with a faintly yellowish color that made them look cheap and unattractive.[22]

Displays of Christmas lights in public venues and on public buildings are a popular part of the annual celebration of Christmas, and may be set up by businesses or by local governments. The displays utilize Christmas lights in many ways, including decking towering Christmas trees in public squares, street trees and park trees, adorning lampposts and other such structures, decorating significant buildings such as town halls and department stores, and lighting up popular tourist attractions such as the Eiffel Tower and the Sydney Opera House. It is believed that the first outdoor public electric light Christmas Holiday display was organized by Fredrick Nash and the Pasadena Chamber of Commerce in Altadena California on Santa Rosa Avenue, called Christmas Tree Lane. Christmas Tree Lane in Altadena has been continuously lit except during WW2 since 1920. Annual displays in Oxford Street, London, England are adored by the public and local businesses alike, have been erected for decades.

From the 1960s, beginning with tract housing in the U.S., it became increasingly common to completely outline the house (but particularly the eaves) with weatherproof Christmas lights. The Holiday Trail of Lights is a joint effort by cities in east Texas and northwest Louisiana that had its origins in the Festival of Lights and Christmas Festival in Natchitoches, started in 1927, making it one of the oldest light festivals in the United States. Fulton Street in Palo Alto, California, has the nickname "Christmas Tree Lane" due to the display of lighted Christmas trees on the sides of the street.[23]

A familiar pastime during the holiday season is to drive or walk around neighborhoods in the evening to see the lights displayed on and around other homes. While some homes have no lights, others may have incredibly ornate displays which require weeks to construct. A rare few have even made it to the Extreme ChristmasTV specials shown on HGTV, at least one requiring a generator and another requiring separate electrical service to supply the amount of electrical power required. In Australia and New Zealand, chains of Christmas lights were quickly adopted as an effective way to provide ambient lighting to verandas, where cold beer is often served in the long hot summer evenings. Since the late twentieth century, increasingly elaborate Christmas lights have been displayed, and driving around between 8 and 10 p.m. to look at the lights has become a popular form of family entertainment. In some areas Christmas lighting even becomes a fierce competition, with town councils offering awards for the best decorated house, in other areas it is seen as a co-operative effort, with residents priding themselves on their street or their neighbourhood. The town of Lobethal, South Australia, in the Adelaide Hills, is famed for its extensive Christmas lighting displays and many residents go to great effort to put on the best light display in the town. Residents from the nearby city of Adelaide often drive up to the town to view them.

In the United States, lights have been produced for many other holidays. These may be simple sets in typical holiday colors, or the type with plastic ornaments which the light socket fits into. Light sculptures are also produced in typical holiday icons.

Halloween is the most popular, with miniature light strings having black-insulated wires and semi-opaque orange bulbs. Later sets had some transparent purple bulbs (a representation of black, similar to blacklight), a few even have transparent green, or a translucent or semi-opaque lime green (possibly representing slime as in Ghostbusters, or creatures like goblins or space aliens). Two types of icicle lights are sold at Halloween: all-orange, and a combination of purple and green known as "slime lights".

Easter lights are often produced in pastels. These typically have white wire and connectors.

Closeup of a mini light

Red, white, and blue lights are produced for Independence Day, as well as U.S. flag and other patriotic-themed ornaments. Net lights have been produced with the lights in a U.S. flag pattern. In 2006, some stores carried stakes with LEDs that light fiber-optics, looking similar to fireworks.

These above light strings are occasionally used on Christmas trees anyway, usually to add extra variety to the colors of the lights on the tree.

Various types of patio lighting with no holiday theme are also made for summertime. These are often clear white lights, but most are ornament sets, such as lanterns made of metal or bamboo, or plastic ornaments in the shape of barbecuecondiments, flamingos and palm trees, or even various beers. Some are made of decorative wire or mesh, in abstract shapes such as dragonflies, often with glass "gems" or marbles. Light sculptures are also made in everything from wire-mesh frogs to artificial palm trees outlined in rope lights.

Christmas lighting does lead to some extensive recycling issues. Every year, more than 20 million pounds of discarded holiday lights are shipped to Shijiao, China (near Guangzhou), which has been referred to as "the world capital for recycling Christmas lights".[24] The region began importing discarded lights around 1990 in part because of its cheap labor and low environmental standards.[24] As late as 2009, many factories would simply burn the lights to melt the plastic and retrieve the copper wire, releasing toxic fumes into the local environment.[24] A safer technique was then developed that involved chopping the lights into a fine sand-like consistency, mixing it with water and vibrating the slurry on a table causing the different elements to separate out, similar to the process of panning for gold.[24] Everything is recycled: copper, brass, plastic and glass.

More and more cities in the U.S., for example, are setting up sensible alternatives and schemes to recycle Christmas lights, with towns organizing drop-off points for handing in old or discarded lights.[25][26]

Installing holiday lighting may also be a safety hazard when incorrectly connecting several strands of lights, repeatedly using the same extension cords, or using an unsafe ladder during the installation process.

Light sculptures can be either flat (most common) or three-dimensional. Flat sculptures are the motifs, and are often on metal frames, but garland can also be attached to outdoor motifs. Indoor motifs often have a multicolored plastic backing sheet, sometimes holographic. 3D sculptures include deer or reindeer (even moose) in various positions, and with or without antlers, often with a motor to move the head up and down or side to side as if grazing. These and other 3D displays may be bare-frame, or be covered with garland, looped and woven transparent plastic cord or acrylic, or natural or goldtone-painted vines. Snowflakes are a popular design for municipal displays, so as not to be misconstrued as a governmentendorsement of religion, or so they can be left up all winter.

^"History of Christmas Trees". History. 2015. Retrieved 5 December 2015. Germany is credited with starting the Christmas tree tradition as we now know it in the 16th century when devout Christians brought decorated trees into their homes. Some built Christmas pyramids of wood and decorated them with evergreens and candles if wood was scarce. It is a widely held belief that Martin Luther, the 16th-century Protestant reformer, first added lighted candles to a tree.

^North Dakota Outdoors, Volumes 27-28. State Game and Fish Department of North Dakota. 1964. p. lvii. The first person to put candles on a Christmas tree was the 16th century German theologian Martin Luther.

^Michelin (10 October 2012). Germany Green Guide Michelin 2012-2013. Michelin. p. 73. ISBN9782067182110. Advent - The four weeks before Christmas are celebrated by counting down the days with an advent calendar, hanging up Christmas decorations and lightning an additional candle every Sunday on the four-candle advent wreath.

^Normark, Helena (1997). "Modern Christmas". Graphic Garden. Retrieved 9 April 2014. Christmas in Sweden starts with Advent, which is the await for the arrival of Jesus. The symbol for it is the Advent candlestick with four candles in it, and we light one more candle for each of the four Sundays before Christmas. Most people start putting up the Christmas decorations on the first of Advent.

^"Candlemas". British Broadcasting Corporation. Retrieved 9 April 2014. Any Christmas decorations not taken down by Twelfth Night (January 5th) should be left up until Candlemas Day and then taken down.